Air-compressor.



Patented Aug. I2, I902. G. H. ABRAMS.

AIR COMPRESSOR.

(Application filed May 15, 1896.)

(No Model.) 2 Sheets-Shem I.

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\ 1 No. 706,87l. Patented Aug. l2, I902. i G. H. ABRAMS.

AIR COMPRESSOR.

(Application filed Maylli, 1896.)

(No Model.) 2 Sheets-Sheet 2.

ATTORNEY UNITED STATES JrEORGE II. ABRAMS, OF

BROOKLYN, NEV YORK.

AIR COIVIPRESSOR.

SPECIFICATION forming part of Letters Patent No. 706,871, dated August 1 2, 1902.

Application filed May 15, 1896.

To all whom it may concern:

Be it known that I, GEORGE 11. ABRAMS, a citizen of the United States, residing in Brooklyn, Kings county, in the State of New York, have invented a certain new and useful Improvement in Air Compressors and Expanders, of which the following is a specification.

1 use the term air to indicate any gas.

My improvements give increased economy and efliciency in the compressing portion of the apparatus by causing the compressed air to act directly on the piston of the compressor in a subsequent stroke, and thus promote the motion of the machine. The fact that the air is primarily compressed to a high tension causes an unusually high temperature to be developed. My engine is especially efficient in heating feed-water or attaining other useful ends by the heat of compression.

I propose to use in connection with this invention a feed-heater, asatisfactory construction of which is disclosed in my United States Letters Patent No. 674,822, issued May 21, 1901. It is sufficient to say now that it utilizes a large proportion of the heat of compression by taking it out of the recently-compressed air and transferring it to water which is about to be forced into the boiler and heated for the generation of steam.

The accompanying drawings form a part of this specification.

Figure 1 is a central section through the compressor and the valves thereof. It will be understood that the piston-rod of the compressor is connected to a strongly-moving reciprocating part (not shown) operated by a steam-engine or other suitable power and that the valve which controls the transmission of air from one end of the compressingcylinder to the other and also two valves which control the ultimate discharge of the air at the moderately high pressure required are operated by eccentrics or cams on the main shaft, (not shown,) so as to be reciprocated at the proper times and to the proper amounts. The three succeeding figures are corresponding sections of portions in different positions. All these latter figures show the mechanism adjusted to pass the air through auxiliary apparatus for utilizing a portion of the heat of compression. Fig. 1

shows the mechanism adjusted to dispense fierial No. 591,641. (Nomodel) with the use of such auxiliary apparatus. Fig. 2 shows the parts with the crank in the same position as in Fig. 1, the mechanism being adjusted to serve with said auxiliary apparatus. Fig. 3 shows the parts when the crank has described about a quarter of a revolution. Fig. 4 shows the same parts after a half-revolution has been completed, and Fi 5 is a diagram view with certain parts in section and showing the compressor connected with the heat-exchanging device.

Similar letters of reference indicate corre-' sponding parts in all the figures where they appear.

A is a fixed portion of the apparatus, super-numerals being used when necessary to designate special parts thereof.

B is a piston, and B the piston-rod, forci bly reciprocated at the proper times to the extent allowable by the length of the cylinder.

0 is a pipe through which air is taken into the cylinder at each stroke either from the atmosphere or from other source at a moderate pressure.

0 is a case inclosing a self-acting valve, (shown in dotted lines, Fig. 1,) which allows the air to be inducted and forbids its return.

C is a hand-wheel operating ascrew C by which the lifting of the valve may be restrained, and thus the amount of air inducted may be regulated under some conditions as, for example, when the compressor is allowed to continue its motion at about the usual rate-but the conditions do not require the full quota of air to be inducted and compressed. When this screw (1 is turned down hard, it holds the valve absolutely and serves as a stop-valve.

Referring more particularly to Figs. 1 to 4, inclusive, air thus inducted into the cylinder through the port a at each movement of the piston 13 to the right is compressed by the movement of the piston to the left and is driven out through a port a past a self-acting valve 1) into a chamber, whichI will designate a and from which it is under ordinary conditions delivered through a port a into a pipe E, through which it is carried to a feed-heater (shown in Fig. 5) or to any other convenient form of device for absorbing and utilizinga portion of the heat developed by the strong compression. The air, still at a high tension and with its temperature only a little reduced, returns through a pipe F and is received through a passage or port a. into the chamber 0. adjacent to said cylinder, from which it is directed atintervals subject to the position of the two connected slidevalves G and G, which are traversed in the chamber a The valve G is formed to allow the air to traverse freely through it longitudinally and to present a tightly-fitting surface on the lower face to control the delivery from the chamber or through a port a into the interior of the cylinder to the right. The other valve G is connected and held at the proper distance therefrom and controls the-flow of the air downward through the port a into the chamber a, effecting this by a tight-fitting surface on its upper face. Both valves G and G are operated by a single rod G The discharge from this (the right hand) end of the cylinder is effected througha port a controlled by two slide-valves I and J, which are provided with ports 1 and j, respectively, operating in the chamber a below. This latter chamber a communicates through a port a with a pipe K, which leads the compressed air away. The treatment of the air after its entrance into the pipe K may be the same as any other example of this class of refrigerating machineryfirst, cooling by one or more treatments with cold water or other means of conveying away the heat and subsequently allowing the air to expand and develop cold, which may be utilized in the manufacture of ice, maintaining a low temperature in any building or apartment, as a brewery or cold-storage room, or attaining any other useful purpose. The air may be brought back after its cold has been utilized, and the same. air may again be compressed and treated many times over. The action of the air on the right face of the piston in the cylinder is productive of two resultsone to assist the motion of the piston to the left and a later at another period to be recompressed, but to a less degree, by the movement of the piston to the right and discharged while under such secondary compression. It is important that the Valves be so worked as to properly favor these results, as both are highly useful at their respective periods. The several valves are worked by devices, as eccentrics or cams, (not shown,) carried by a revolving shaft. Such means may obviously be adjusted to give a wide range of motion, each to its respective valve. I have not deemed it necessary to show the mechanism, but simply to make clear the motions induced. the two valves G and G, the latter taken together as one, are reciprocated by different means, and each may be adjusted independently of the others. The valve G, with its companion G, commences to move to the right at such time as to uncover the-port a when the piston B is at or near the right ex- The valves I and J and trerne of its motion and ready to commence itsmovementtotheleft. Itsoonclosesagain, but the strong pressure thus received from the pipe F and its connections acts on the right face of the piston and urges it strongly to the left. This condition continues, but with the pressure rapidlylowering by reason of the movement of the piston to the left providing increased space for the air. The valves G and G are so related that there is a position (indicated in Fig. 3) in which a small quantity is received at an intensely high pressure and fills the chamber a, but it cannot yet get into the cylinder. This condition is attained before the piston has reached the limit of its right-hand movement, and at the time'that the piston reverses its motion and commences to move to the left the valves G G have moved so far to the right as to uncover the port ct and allow the air to flow into the cylinder, and thus to efficiently act on the piston and aid its motion during the useful movement to the left throughout nearly its whole stroke with the force due to the expansion of the large quantity of intensely-compressed air which is contained in the extended connections of the chamber (1 As the stroke of the piston to the left is terminating the movement of the valves G G to the left covers and closes the port a and prevents any further flow from this The return movement of the pis-.

quarter. ton to the right recompresses the air, but to a less extent than before, as will now be explained. Said piston commences its movement to the right against only a weak pressure on its right face, but as its movement to the right progresses it reaches a point after the completion of some two-thirds of the movement where the right face is subject to the pressure obtaining in the final delivery-pipe K, Which is less than that to which it has been before compressed. At that time the valves I and J present their ports 2' andj in line and allow the air to flow directly through these ports into the pipe K.

It is important to liberate at just the right time the air which has been recompressed in the right-hand portion of the cylinder. If the discharge-port opens too soon, air will commence to come back through it before the rising pressure in the cylinder, due to the movement of the piston to the right, shall compress it up to the pressure. If, on the contrary, the opening is delayed too long, it will accumulate a pressure in the cylinder which resists the motion uselessly, accumulating a pressure only to be wasted by its free discharge through the port at a later period. I provide for opening the port more instantaneously than would be otherwise practicable by the use of the two slides I and J, each having a port therein, the two matching together and the lower one matching upon the base with accuracy. These valves are operated by mechanism, (not shown,) so that they are moved in opposite directions. By reason of this construction and this mode of operation the two ports 4 andj come into line, so as to open the port, and go out of line, so as to close the port, with twice the rapidity of a single slide moving at the same rate. The action described effects a double induction-one through the pipe into the left end of the cylinder and afterward through the pipe F and the controlling means shown into the right end of the cylinder-and a double delivery first from the left end through the pipe E at a very high pressure, and consequently at a high temperature, to allow much of the heat of compression to be received outside under such conditions for temperature as to be available for useful purposes in the arts, and a second delivery through the pipe K at a lower tension, which is sufficient by its subsequent cooling and expansion to attain the refrigerating action required.

It may be desirable under some circumstances to work the apparatus without taliing away and utilizing the heat through the feed-heater-in other words, to omit the driving of the air out through the pipe E and the receiving back again, slightly lowered in temperature, through the pipe F and to transmit it directly from the chamber a into the chamber a. I attain this by making the upper portion of the chamber a to receive a tightlyfitting plug M, which is capable of being revolved or partially revolved when required. I have shown this as screw-threaded, such being a convenient way of holding the plug engaged, notwithstanding the strong pressure to which its lower end is subjected; but other means may be employed for holding it. I11 the interior of the plug is a port 665, which is quartering to the port a Fig. 1 shows this plug thus adjusted. Figs. 2, 3, and 4 show it adjusted to utilize the pipe E and F and the feed-heater or other heat-utilizing apparatus adapted to coact therewith.

Fig. 5 represents in outline a convenient form of the apparatus for utilizing the high temperature of the compressed air by means of a heat-exchanger, which transmits it to another fluid, which latter may be water, for feeding a boiler or for other uses.

The junction of the pipes E and F is effected through anumber of convolutions inclosed in a casing 0, receiving the water at an elevated temperature from the parts above and discharging it through the bottom pipe 0 at a still higher temperature, acquired from the convolutions of the pipes E F.

P is a pipe through which the water to be heated is received, and I a series of convoluted pipes in which the water descends, and I a further series of convoluted pipes in which the water further descends in the casing O. The air of secondary compression discharged through the pipe K of the compressor is led around and presented successively to these heating convolutions P P inclosed in a suitable casing Q. Thence the air is conveyed through a suitable pipe R to a condenser S, in which it is presented to liberal provisions, as tocold-water pipes or otherwise, for cooling it to or near the ordinary temperature of the atmosphere. After being thus cooled the air is conducted through a pipe T, insulated passage T, and pipe T to an engine U, where it is caused to act expansively on a piston (not shown) and in the act of its eX- pansion to attain the two important ends of developing power, which will aid the steamengine (not shown) in driving the compress ing-piston B, and producing the cold, which is subsequently utilized in the ordinary manner in the manufacture of ice or other work.

Modifications may be made without departing from the principle or sacrificing the advantages of theinvention. The several chambers a and a may be made more capacious, when desired, by the connection of a sufiicient vessel through sufficient passages, (not shown,) such vessels being spheroidal to enable them to withstand the strong internal pressure.

Having described my invention, what I claim is-.-

1. In a combined air compressor and expander, the combination of a cylinder and piston for compressing air to a high tension, an outlet therefrom adapted for connection with a suitable cooling device, an inlet thereto adapted to receive the air upon its return from said cooling device, means whereby the compressed air may expand in the rear of the piston, and suitable means whereby the air first compressed may be led directly to the rear of the piston instead of first passing through a cooling device, substantially as described.

2. In a combined air compressor and expander, the combination of a cylinder and piston for compressing air to a high tension, an outlet therefrom adapted for connection with a suitable cooling device, an inlet thereto adapted to receive the air upon its return from said cooling device, means whereby the air may expand in the rear of the piston, means permitting the piston to partially recompress the air on its return stroke and suitable means whereby the air first compressed may be led directly to the rear of the piston instead of first passing through a cooling device, substantially as described.

In a combined air compressor and expander, the combination ofa cylinder and piston for compressing air to a high tension, a valve-controlled outlet from said cylinder adapted to communicate with the cylinder at the rear of the piston to permit the air to expand thereat, and valve mechanism adapted to be positively operated from a moving part to permit the expanded air to be recom pressed on the return stroke of the piston but at a lower degree than that of its primary compression and allow its discharge from the cylinder while under such secondary compression for service expansively external to the cylinder.

4. In a combined air compressor and expander, the combination of a cylinder and piston, a passage for establishing communication between the front and rearends of the cylinder by Way of a chamber, a check-valve and a revoluble plug in said passage, the latter adapted to permit the compressed air to be directed to the aforesaid chamber or led away, suitable valves in said chamber controlling the inlet and outlet therefrom, and a valve-controlled passage from the cylinder at the rear side of the piston.

5. In a combined air compressor and expander, the combination of a cylinder and piston, a passage for establishing communication between the front and rear ends of the cylinder by way of a chamber, a check-vave in said passage, valve provision adapted to return the compressed air through the passage and chamber to the back end of the cylinder, a second chamber having a port communicating with the rear end of the cylinder and provided with an outlet-port; and valve mechanism in said second chamber controlling the outlet and adapted to be positively operated by a moving part to permit the expanded air to be recompressed on the return stroke of the piston butat a lower degree than that of its primary compression.

6. In apparatus for compressing air, the combination of a cylinder, a piston therein, a valved passage-way for externally conveying the compressed air directly from the front end of said cylinder, at second passage-Way for establishing communication between the front and rear ends of said cylinder, a revoluble plug in said second passage way provided with a suitable port whereby the compressed air may be returned to the rear of the piston to expand thereat, and Valve mechanism adapted to be positively operated from a moving part to permit the expanded air to be recompressed on the return stroke of the piston but at a lower degree than that of its primary compression and allow its discharge from the cylinder while under such secondary compression.

In testimony that I claim the invention above set forth I affiX my signature in presence of two witnesses.

GEORGE H. ABRAMS.

Witnesses:

WILLIAM PATTON, M. F. BOYLE. 

